According to the New York Times Everyday Dictionary copyright 1982:

pro-ac-tive adj. favoring the first learned: -- inhibition

that is, being inhibited so as to continue doing something the way you've always done it. Of course, that is the opposite of how many use the word. Therefore, the word is really useless. You can only determine the user's meaning from the context or from how the word is used.

I've never heard it used that way. Just assume it means acting in a way that will leave you ready for an expected occurrence rather than waiting for it to happen and trying to clean up afterwards and you'll be OK 99 times out of 10.